This list is an attempt to compile the locations of the biggest sites and
those with extensive cross-references.  Please let me know other sites
*that fall into these categories* or *categories not included*.  The FAQ
can't list everybody's favorite site, but it should list sites that
cross-reference most people's favorites.

 Indices
  *  AstroWeb: Astronomy/Astrophysics on the Internet [multiple mirror sites]

   -   _NRAO, US East_, <URL:http://fits.cv.nrao.edu/www/astronomy.html>,

   -   _STScI, US East_, <URL:http://www.stsci.edu/net-resources.html>,

   -   _CDS, France_, <URL:http://cdsweb.u-strasbg.fr/astroweb.html>,

   -   _ESO_, <URL:http://ecf.hq.eso.org/astroweb/yp_astro_resources.html>,

   -   _ESA, Spain_, <URL:http://www.vilspa.esa.es/astroweb/astronomy.html>,

   -   _ANU, Australia_, <URL:http://www.mso.anu.edu.au/%7Eanton/astroweb/>,

  *  _Students for the Exploration and Development of Space_,
 <URL:http://www.seds.org/>, (SEDS) (Images, Info, and Software Archive)

   -   _anonymous ftp_, <URL:ftp://seds.lpl.arizona.edu/pub/>,

   -   _astroftp (text)_,
  <URL:ftp://seds.lpl.arizona.edu/pub/faq/astroftp.txt>, list

   -   _astroftp (HTML)_,
  <URL:ftp://seds.lpl.arizona.edu/pub/faq/astroftp.html>, list

  *  _Galaxy_, <URL:http://galaxy.einet.net/galaxy/Science/Astronomy.html>,

  *  _Google Groups_, <URL:http://groups.google.com/>,

 Data Archives and Catalogs
  *  _JPL Solar System Dynamics_, <URL:http://ssd.jpl.nasa.gov/>,
 ("information [about] all known bodies in orbit around the Sun.")

  *  _Centre de Donnees astronomiques de Strasbourg_,
 <URL:http://cdsarc.u-strasbg.fr/>, (in English and includes SIMBAD)

  *  _NSSDC Astrophysics Data_, <URL:http://nssdc.gsfc.nasa.gov/astro/>,
 (space missions and catalog data)

  *  _Astronomical Data System_, <URL:http://adswww.harvard.edu/>,
 (professional journals, conference proceedings, data)

  *  APS _Catalog of the Palomar Observatory Sky Survey_,
 <URL:http://isis.spa.umn.edu/>,

  Images & Simulations
  *  _Astronomy Picture of the Day_,
 <URL:http://antwrp.gsfc.nasa.gov/apod/astropix.html>,

  *  _SkyView_, <URL:http://skyview.gsfc.nasa.gov>, (digitized images of any
 sky coordinates, multi-wavelength)

  *  _Jet Propulsion Laboratory_, <URL:http://www.jpl.nasa.gov/>, (JPL)

  *  The Nine Planet _Planetary Picture List_,
 <URL:http://seds.lpl.arizona.edu/billa/tnp/picturelist.html>,

  *  _NASA JSC Digital Image Collection_, <URL:http://images.jsc.nasa.gov/>,
 (mostly Earth and spacecraft)

  *  _U.S.  Geological Survey_,
 <URL:http://www-pdsimage.wr.usgs.gov/PDS/public/mapmaker/mapmkr.htm>,

  *  _The Web Nebulae_, <URL:http://seds.lpl.arizona.edu/billa/twn/>,

  *  _Messier Database_, <URL:http://www.seds.org/messier/>,

  *  _Solar System Live_, <URL:http://www.fourmilab.ch/solar/solar.html>,

  Societies, Institutions, Publishers
  *  _American Astronomical Society_, <URL:http://www.aas.org/>,

  *  _Royal Astronomical Society_, <URL:http://www.ras.org.uk/>,

  *  _American Association of Variable Star Observers_,
 <URL:http://www.aavso.org/>,

  *  _NASA_, <URL:http://www.nasa.gov/>,

  *  _Space Telescope Electronic Information Service_,
 <URL:http://www.stsci.edu/resources/>,

  *  _Sky and Telescope_, <URL:http://www.skyandtelescope.com/>,

  *  USGS _Astrogeology Research Program_,
 <URL:http://astrogeology.usgs.gov/>,

  Related Usenet newsgroups (see also  A.01)
  *  _*sci.physics*_, <URL:news:sci.physics>,: Physical laws, properties, etc.

  *  _*sci.physics.particle*_, <URL:news:sci.physics.particle>,: Particle
 physics discussions

  *  *sci.space.**: Discussions of space policy, travel, technology, etc.

  *  *talk.origins*: Discussions of creationism vs.  evolution, the Big Bang,
 and other science topics

  Related FAQs
 Many related newsgroups have FAQ's.  Most can be obtained by anonymous ftp
from _rtfm.mit.edu_, <URL:ftp://rtfm.mit.edu/pub/usenet-by-hierarchy/sci/>.

  FAQ for *sci.physics*
    available via _anonymous ftp_,
<URL:ftp://rtfm.mit.edu/pub/usenet-by-hierarchy/sci/>, and on the
Web from various mirrors including _US West Coast mirror_,
<URL:http://math.ucr.edu/home/baez/physics/>, _European mirror_,
<URL:http://www.desy.de/user/projects/Physics/>, and _Australia mirror_,
<URL:http://hermes.physics.adelaide.edu.au/%7Edkoks/Faq/>.

  FAQ for *sci.space*
    available via _anonymous ftp_,
<URL:ftp://rtfm.mit.edu/pub/usenet-by-hierarchy/sci/space/>,

  Astro/Space Frequently Seen Acronyms
    available via _anonymous ftp_,
<URL:ftp://rtfm.mit.edu/pub/usenet-by-hierarchy/sci/space/>,

  FAQ for *sci.astro.planetarium*
    available via the _Web_,
<URL:http://www.lochness.com/pltref/sapfaq.html>,

  FAQ for *sci.skeptic*
    available via _anonymous ftp_,
<URL:ftp://rtfm.mit.edu/pub/usenet-by-hierarchy/sci/>,

  FAQ for *talk.origins*
    available from the _talkorigins_,
<URL:http://www.talkorigins.org/origins/faqs-qa.html>, Web site

  FAQ for relativity
    _Usenet Relativity FAQ_,
<URL:http://www.weburbia.com/physics/relativity.html>,

  FAQ for black holes
    _Black Holes FAQ_,
<URL:http://cosmology.berkeley.edu/Education/BHfaq.html>,

  FAQ for calendars
    _Calendar FAQ_, <URL:http://www.tondering.dk/claus/calendar.html>,

  FAQ for supernovae and supernova remnants
    _Supernovae and Supernova Remnants FAQ_,
<URL:http://www.talkorigins.org/faqs/supernova/>,

  Lecture notes, essays, compilations, etc.
  *  _The Nine Planets_, <URL:http://seds.lpl.arizona.edu/billa/tnp/>,

  *  Nick Strobel's _Astronomy Notes_, <URL:http://www.astronomynotes.com/>,

  *  _The Constellations and Their Stars_,
 <URL:http://www.astro.wisc.edu/%7Edolan/constellations/>,

  *  John Baez's _General Relativity Tutorial_,
 <URL:http://math.ucr.edu/home/baez/gr/gr.html>,

  *  _The Astronomy Cafe_, <URL:http://www.astronomycafe.net/>,

  *  _Virtual Trips_, <URL:http://antwrp.gsfc.nasa.gov/htmltest/rjn_bht.html>,
 to black holes and neutron stars

  *  _Bad Astronomy_, <URL:http://www.badastronomy.com/>,

  *  _Powers of 10_,
 <URL:http://micro.magnet.fsu.edu/primer/java/scienceopticsu/powersof10/>,---The
 Size of the Universe (interactive Java tutorial)